Ars Nova and Sphere Ensemble team up for self-led concerts

There are choirs that sing without a conductor, and orchestras that do likewise. But combined choral-orchestral concerts usually require a conductor.

Boulder’s Ars Nova Singers and Sphere Ensemble hope to change that when they perform “Britten and Beyond,” a collaborative, conductor-less concert of music by Benjamin Britten and Arvo Pärt, Friday, Oct. 11, in Denver and Saturday, Oct. 12, in Boulder.

In case the name is new to you, Sphere Ensemble was founded in 2011.Approximately a dozen string players who usually perform without a conductor, Sphere has members who play in the Boulder and Greeley Philharmonics, Colorado, Fort Collins and Cheyenne symphonies, Colorado and Central City Opera, Mont Alto Motion Picture and Tango Orchestra, Danielle Ate the Sandwich and Blow the Vault.

Now going into its 37th season, Ars Nova is a familiar part of Boulder’s music scene. An a cappella choir of 36 voices, they are known for their carefully prepared performances of music from the Renaissance and contemporary times.

Together, the two groups are quite a few people to put up onstage without a conductor.

“I thought [performing without a conductor] would be an interesting challenge,” Tom Morgan, director of Ars Nova, comments. “We’ve done numerous collaborations with other orchestras, but I always like to do things in a slightly different way.

“I liked watching the Sphere Ensemble perform, how they interact and cue each other, so I thought, how can we adapt that aesthetic to what we do together? It’s actually a good thing to do at the beginning of the season, because it really gets the ensemble tuned in to each other, and less reliant on a conductor.”

Sphere Ensemble founder and director Beth Rosbach agrees that the concert will be a challenge.

“To throw a choir into the mix means everybody’s going to have to be very aware of what’s going on across the stage,” she says. “Everybody has to be a leader. Ars Nova is such a tight group that they’re perfect for this.”

The program begins as a tribute to Britten, born 100 years ago.

“There’s a fair number of groups around the country that are doing Britten retrospectives,” Morgan notes. “But when we were working together [with Sphere] on what we might do, we thought we should transition out of Britten, into something more contemporary.”

Pärt was chosen for “something more contemporary” because he admired Britten and wrote an “In Memoriam” to the older composer that will form a bridge between the two. Besides, Morgan adds, “Britten had a significant impact on choral music of the 20th century, not least of which is going toward Pärt.”

The concert will open with Britten’s “Hymn to St. Cecilia,” the patron saint of music whose Saint’s Day is also Britten’s birthday, Nov. 11, performed by both groups. That will be followed by two little known a cappella vocal pieces, “Chorale after an Old French Carol” and “Advance Democracy.” Sphere will close the first half of the concert with Britten’s charming “Simple Symphony” for strings, based on themes he wrote as a child.

After intermission, Sphere will make the transition with Pärt’s “Cantus in Memoriam Benjamin Britten,” and the two groups will perform the U.S. premiere of his “Salve Regina.” And then, Morgan says, “Each group is going to do an encore piece, and then one surprise piece at the end that we’re going to do together.”

Audience members will just have to wait to the end to find out what that is.

It’s hard to single out any one piece from such a varied program, but the U.S. premiere of Pärt’s “Salve Regina” will be a high point for many listeners. An Estonian composer known for sacred works characterized by simple harmonies and slow, steady rhythms — a style the composer calls tintinnabuli, like the ringing of bells — Pärt has achieved a cult popularity in the U.S.

Composed in 2001, the “Salve Regina” represents a newer trend.

“I think this piece has evolved [from the earlier style],” Morgan says. “Even though it’s not overly complex in musical details, it still has a depth and a sonority that people want to hear, and that many people really, really respond to. There are some beautiful moments.”

Rosbach also focuses on the sound of Pärt’s music.

“I think people are in for such a treat,” she says. “It’s one thing to listen to recordings of his works, it’s a completely different thing to experience it live. It’s like being transformed into another world, because of the incredible way that he layers sound.”

Ars Nova Singers and Sphere Ensemble perform at 7:30 p.m. Friday, Oct. 11 at Saint Paul´s Lutheran Church in Denver, and at 7:30 p.m. Saturday, Oct. 12 at First United Methodist Church in Boulder. Tickets are $24 for adults. Visit http://arsnovasingers.com or www.sphereensemble.org for more details.